Adjective that defines an Army soldier who, in either combat or casual settings: keeps perfect uniforms far above required standards, with no loose threads or stains or wrinkles, and all required insignia and medals exactly where they should be; and, has superb dignity and bearing, ramrod straight yet behaving with the ease born of confidence--in short, the model of appearance for all soldiers to follow.

The term was heard by this writer in 1977-1978 at Fort Bragg, NC, post-Vietnam era. It was considered the highest compliment that could be paid by one soldier to another. It was always given to male soldiers, as female soldiers were so few at the time and it tended to be a "guy thing." It might derive from one of a number of related words in old German, Dutch, or English meaning "tight," "tense," or "strict" (see "strak" in Wiktionary-dot-org).

"Listen up! Look at Sergeant Cooper here. This is the living, breathing definition of strack. Not a hair out of place, clean shaven, pressed uniform, boots so shined you could shave using them as mirrors. I want every one of you men to look exactly like him in formation tomorrow morning! Anyone who doesn't is going to do the Dying Cockroach until sundown! Do you hear me?"